Dynamite composition



Patented Aug. 3, 1926.. l

' UNITED}: STATES I 1,594,851 Paras-r orrica.

WENDELL R. SWINE, OF WHIHINGTON, DELAWARE, ASSIGNOB 'I'O E. I. DU PONTDE moons &. GOHPANY, OF WILMINGTON, DELAWARE, A. CORPORATION OF'DELA-WABE.

Ho Drawing.

This invention relates to dynamite composltions, and consistsessentially in the use of ,balsa wood as a new absorbentmaterial for theliquid high explosive component of dy- 8 namite.

In an ordinary dynamite containing nitroglycerine, the material used toabsorb nitroglycerine will depend upon the percentage of nitroglycerinein the explosive. Thus, 10 for example, a so-called straight dynamitecontaining 60% of nitroglycerine usually contains approximately 18% ofwood flour or. wood pulp, whereas a dynamite containing 40%nitroglycerine may contain about 10% of wood our or wood pulp, and adynamite containing of nitrogl cerine may be made without any wood ouror wood pulp at all, the other in edients such as sodium nitrate, cornmeal, our, etc., having suificient power of absorption to retain thenitroglycerine without the latter exuding from the dynamite. i

have discovered thatdynamites having new and distinctive properties maybe obi tained by using finely divided balsa wood as the chief absorbentmaterial for the nitroglycerine or other liquid high explosiveconstituent. -My invention contemplates the use of balsa wood, reparedin a way to be described below, 1n place of all or a part of the woodpul or wood flour ordinarily used. Balsa. wood Ochroma Zagopue) is atropical wood which is distinctive in that it has a very low specificgravity. Commercial balsa 5 wood hasa specific gravity of from 0.115-

0130. The reason for this extreme lightness is its loose structure andthe softness of its tissue. '1 have found that if balsa wood issubjected to the ordinary procedure in manufacturing wood flour, such asgrinding in suitable mills, for example buhrstone mills or othersuitable attrition mills, the wood pul or wood flour so produced retainsthe 'ghtness of the original wood and J provides a very satisfactoryabsorbent for nitroglycerine. Because of the extreme lightness of thewood flour or wood pulp so produced, a given weight will absorb a higherpercentage of nitroglycerine than will l wood pulp or wood flour madefrom ordinary wood, such as spruce, fir, pine, etc. taking advantage ofthis fact, I can produce a 60% dynamite containing a lower .percentageof wood pulp or wood flour than is fineness.

DYNAMITE COMPOSITION. I

Application filed April 18, 1922. Serial No. SIS 2,844.

ordinarily used when wood pulp or wood flour made from ordinary northernwoods is employed. Thus, for example, a dynamit e can be made with from12-15% of wood flour made from balsa wood as compared with 20% of woodpulp or wood flour made from ordinary northern woods.

I have also discovered that sawdust produced as a waste product of balsawood by, the ordinary methods of wood working may be used to greatadvantage in dynamite compositions where the .percentage ofnitroglycerine is not high, and where a lowdensity explosive is desired.Thus, for example, in explosives of the permissible type such as areused in coal mines, it is sometimes desirable touse a very low densityexplosive. The explosives now in use ordinarily have a densitycorresponding toa weight of 160-180 grams for a cartridge 1%" indiameter by t 8" long. B the use of a specially high grade wood our orwood pulp, it is possible to obtain a density corresponding to a weightof about 145 grams for a cartridge 1 A in diameter .by 8" long.- I havediscovered that by using sawdust made from balsa wood, I can produce apermissible explosive having a density correspondingto a weight ofapproximately 125 grams for a cartridge 1%" in diameter by 8' long. Thesawdust for use in compositions of this type may vary within quitewidelimits as to That which I have found to be most suitable is of suchafineness that none 'isheld on a 10 mesh screen and from '10- 30% passesa-40 mesh screen. Similar results can be obtained, using 'wood flour orwood pulp made from balsa wood. Asanexample of such an explosive, I citethe following Per cent. Nitroglycerine 10' Ammonium nitrate 75 Sodiumnitrate 5 Balsa wood sawdust 10 It will, of course, be understood that Imay vary this-composition greatly without departing from the spirit ofthe. invention. Thus,'for example, I may use tetranitrodi-- glycerine inplace of-nitroglycerine in order to make the ex losive low reezing, or Imay omit sodium nitrate entirely or mc'rease its percentage appreciably.Instead of sodium nitrate, I may use sodium chloride or I may use any ofthe well-known methods for depressing the temperature of the flame inorder to secure an explosive which will be safe to use in dusty andgaseous coal mines. For a portion of the balsa wood, I may substituteother carbonaceous materials, such as corn meal, ivory nut meal, flour,etc.

The most important ranges of proportions may be indicated as follows(for permissible explosives) I Percent. Nitroglycerine from 7-15Ammonium nitrate from 4085 Sodium nitrate from 20 Sodium chloride "from"0-20 Balsa wood pulp or flour fi'om -15 I claim:

1. An explosive composition characterized b its low density andcomprisin from about 7 to of a normally liqu1d high explosive, fromabout 5 to 15% of finely divided balsa wood, and ammonium nitrate.

2. An explosive composition characterized b its low density andcomprisin from aliout 7 to 15% of a normally liquid hi h explosive, fromabout 5 to 15% of finely ivided balsa wood, from 40 to 85% of ammoniumnitrate, and a salt adapted to reduce the flame temperature uponexplosion of the composition.

3. An explosive composition characterized by its low density about 7 to15% of nitroglycerine, from about 5 to 15% of finely divided balsa wood,and ammonium nitrat 4. An explosive composition characterized by its lowdensity and comprisin about 10% of nitroglycerine, about 75% o ammoniumnitrate, about 5% of sodium nitrate, and about 10% of finely dividedbalsa wood.

In testimony whereof I aflix my signature.

WENDELL R. SWINT.

and comprising from,

